1. Technical Field
The present disclosure relates to a wiring board having an electrode pad and an alignment mark and a method of manufacturing the wiring board.
2. Background Art
Various configurations of a wiring board (electronic device) have been proposed that mount components such as semiconductor chips. In recent years, there has been a significant demand for making a wiring board on which a semiconductor chip is mounted thin in thickness and small in size, as the semiconductor chip is made thin in thickness and small in size.
As a method of manufacturing the wiring board to be thin in thickness, for example, a so-called build-up method has been known. In the build-up method, a build-up layer (build-up resin) made of epoxy resin is stacked on a core board to form an interlayer insulating layer, thereby manufacturing a wiring board.
The core board is made of prepreg or the like. In a process of manufacturing a wiring board, the core board supports a soft built-up layer that has not been cured yet. In addition, the core board prevents the wiring board from being warped as the built-up layer is cured. However, when trying to make the core board further thinner in the aforementioned build-up method, there is a problem in thickness of the core board serving as a base of the wiring board.
In order to make the core board further thinner in the build-up method, there has been proposed a method in which a wiring board is formed on a support plate for supporting (build-up layer) the wiring board and then the support plate is removed (e.g., see Japanese Unexamined Patent Application Publication No. 2005-5742).
However, since adhesion is not strong between the support plate made of metal and the build-up layer made of resin, a countermeasure is needed to improve adhesion. As an example thereof, a method of improving adhesion to resin by roughening a metal surface has been studied.
However, when the support plate is roughened, the state of the roughened surface thereof is transferred to a surface of the wiring board. For example, when an alignment mark used for alignment (positioning) is formed on the surface of the wiring board coming into contact with the support plate, a surface of the alignment mark is roughened. Accordingly, it is difficult to recognize the alignment mark in positioning the wiring board, and thus reliability in process precision may decrease.